Abstract
AIM: BRCA1/2 mutation carriers with primary breast cancer (PBC) are at high risk of contralateral breast cancer (CBC). In a nationwide cohort, we investigated the effects of chemotherapeutic agents given for PBC on CBC risk separately in BRCA1 and BRCA2 mutation carriers.
PATIENTS AND METHODS: BRCA1 or BRCA2 mutation carriers with an invasive PBC diagnosis from 1990 to 2017 were selected from a Dutch cohort. We estimated cumulative CBC incidence using competing risks analysis. Hazard ratios (HR) for the effect of neo-adjuvant or adjuvant chemotherapy and different chemotherapeutic agents on CBC risk were estimated using Cox regression.
RESULTS: We included 1090 BRCA1 and 568 BRCA2 mutation carriers; median follow-up was 8.9 and 8.4 years, respectively. Ten-year cumulative CBC incidence for treatment with and without chemotherapy was 6.7% [95%CI: 5.1-8.6] and 16.7% [95%CI: 10.8-23.7] in BRCA1 and 4.8% [95%CI: 2.7-7.8] and 16.0% [95%CI: 9.3-24.4] in BRCA2 mutation carriers, respectively. Chemotherapy was associated with reduced CBC risk in BRCA1 (multivariable HR: 0.46, 95%CI: 0.29-0.74); a similar trend was observed in BRCA2 mutation carriers (HR: 0.63, 95%CI: 0.29-1.39). In BRCA1, risk reduction was most pronounced in the first 5 years (HR: 0.32, 95%CI: 0.17-0.61). Anthracyclines and the combination of anthracyclines with taxanes were associated with substantial CBC risk reduction in BRCA1 carriers (HR: 0.34, 95%CI: 0.17-0.68 and HR: 0.22, 95%CI: 0.08-0.62, respectively).
CONCLUSION: Risk-reducing effects of chemotherapy are substantial for at least 5 years and may be used in personalised CBC risk prediction in any case for BRCA1 mutation carriers.
Original language | English |
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Pages (from-to) | 98-107 |
Number of pages | 10 |
Journal | Breast |
Volume | 61 |
Early online date | 14 Dec 2021 |
DOIs | |
Publication status | Published - Feb 2022 |
Keywords
- BRCA1
- BRCA2
- Breast cancer
- Chemotherapy
- GRADE
- MUTATION CARRIERS
- NEOADJUVANT CHEMOTHERAPY
- PROGNOSTIC-FACTORS
- Risk factors
- SURVIVAL
- Secondary